Test of turbulence models for natural convection in an open cubic tilted cavity

Piña-Ortiz, A.; Hinojosa, J.; Maytorena, V.M.

doi:10.1016/j.icheatmasstransfer.2014.08.011

Cited by 15 publications

(8 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be seen from A realizable k-ε turbulent model will be used since it is known to have a good performance with indoor airflows, temperature and pressure in closed structures. [41][42][43][44][45] In the turbulence model, the enhanced wall treatment with pressure gradient effects and thermal effects, and the full buoyancy effect under gravity have been taken into account, but the viscous heating is ignored since the air flows in the living room at a low speed and there is almost no mechanical energy be converted into heat.…”

Section: Computational Model and Meshmentioning

confidence: 99%

Thermal performance of a mine refuge chamber with human body heat sources under ventilation

Zhang

Wang

et al. 2019

Applied Thermal Engineering

View full text Add to dashboard Cite

This paper investigated the dynamic coupling heat transfer characteristics of rock and air in a Mine Refuge Chamber (MRC) under ventilation. In the current work, a comprehensive fiftyperson MRC model combining human-body heat sources and ventilation is established, the proposed model is validated against available experimental data with deviation less than 4%. Furthermore, sensitivity analysis is performed to investigate the influence of several control parameters such as heating rate, ventilation and wall area in a MRC through using numerical simulation. Results indicated that: (ⅰ) the heat transfer process in a MRC will reach a stage of air temperature slow increase (ATSI) in less than 0.5 h. The air temperature rises linearly with the square root of time during the ATSI stage; (ⅱ) for a MRC built in a sandstone seam with an initial rock temperature of less than 27 °C, the average air temperature will not exceed 35 °C in 96 h when the ventilation volume rate is 0.3 m 3 /min per person; (ⅲ) the rate of temperature rise in MRC is proportional to the rate of heat generation, but it is inversely proportional to the thermal conductivity, density and thermal capacity of the rock, as well as the ventilation volume rate and the wall area; (ⅳ) an empirical correlation for the MRC average air temperature is developed while the supply air temperature equals to the initial rock temperature. Keywords：Underground; Mine refuge chamber; Air temperature prediction; Ventilation; Heat transfer coefficient; Human body heat sources. Nomenclature a Constant in K expression V Ventilation volume for MRC, m 3 /h A w Wall area of MRC, m 2 x, y Coordinate direction vector b Constant in K expression Subscripts B Temperature variable, °C a Air c Constant in K expression num Numerical data C a Specific heat capacity of air, J/(kg• K) exp Experimental data C p Specific heat capacity of rock, J/(kg• K) Greek symbols d Constant in K expression α Surface heat transfer coefficient, W/(m 2 • K) i, j Constant in B expression Θ Difference k Constant in B expression ρ Density of rock, kg/m 3 K Rate for air temperature increasing, °C/s 0.5 ρ a Density of air, kg/m 3 l Constant in B expression λ Thermal conductivity of rock, W/(m• K) L Temperature variable, °C τ Heat time, h L c Perimeter of cross-section tunnel, m Acronyms m, n Constant in K expression ATSI Air temperature slow increase p Pressure, Pa CE Critical equilibrium Q Total heat generation rate in MRC, W MRC Mine refuge chamber r 0 equivalent radius of cross-section tunnel, m MMRC Movable mine rescue capsules T Temperature, °C PCM Phase change materials T 0 Initial rock temperature, °C

show abstract

Section: Computational Model and Meshmentioning

confidence: 99%

Thermal performance of a mine refuge chamber with human body heat sources under ventilation

Zhang

Wang

et al. 2019

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…Nu dY (18) Characteristic velocity (V): The determination of characteristic velocity is another important parameter in natural convection LBM simulation. It can be estimated from the following equation [39,40]:…”

Section: Problem Statement and Mathematical Formulationmentioning

confidence: 99%

“…(17)) and average Nusselt number (Eq. (18)) calculated at the heated wall. Local as well as average Nusselt are plotted for open ended cavity with different fluids for Rayleigh number of 10 4 ࣘ Ra ࣘ 10 6 .…”

Section: Heat Transfer Characteristicsmentioning

confidence: 99%

“…The increase of Ra beyond this value leads to occurrence of number of recirculating loops in the flow and sharp spatial fluctuations of heat transfer within the annulus. Few recent studies of natural convection in an open ended cavity are reported by [16][17][18]. Mahmoudi et al [16] analyzed the MHD natural convection heat transfer nanofluids-filled open cavity with non uniform boundary condition in the presence of uniform heat generation/absorption by using lattice Boltzmann method.…”

Section: Introductionmentioning

confidence: 99%

“…The absolute values of stream-function decrease significantly with Hartmann number while these values increase by increasing Rayleigh numbers. More recently, Pina-Ortiz et al [18] presented a comparison of six turbulence models and experimental temperature profiles for the turbulent natural convection in a tilted open cubic cavity. The lowest absolute average percentage difference for the experimental and numerical temperature profiles was for the rk − ε t model and the highest was for the sk − ω model.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations